A DAY OUT WITH BRISSY’S TURTLES

Brisbane’s Moreton Bay has many wonderful dive sites packed with a diverse range of species. On every dive you will encounter tropical fish, pelagic fish, sharks, rays, a wealth of invertebrate species and even turtles. Moreton Bay is one of Australia’s most important turtle habitats, so it is quite common to see one or two turtles on a dive, but on a recent dive trip I had some very memorable turtle encounters.
    I was diving from the charter boat Nautilus, an 18m long vessel run by Nautilus Scuba Centre. This boat is one of the most comfortable dive boats on the east coast. Each weekend, and midweek on demand, Nautilus explores the best dive sites off Moreton Island and North Stradbroke Island.
    Our destination today was North Stradbroke Island, and light southerly winds meant the seas were relatively calm, apart from a one-metre ground swell. Our first dive was to be at Shark Alley, on the southeast corner of Flat Rock.
    Shark Alley is one of the best places to observe grey nurse sharks over winter, but we were a little early since it was May. However, there is always great marine life at this site even if you don’t encounter a grey nurse.
    After a dive brief, my buddy Peter and I quickly geared up to jump into the wonderful blue water surrounding the boat. The visibility was brilliant, around 30m, while the water temperature was a very comfortable 22 degrees, Brissy diving is pretty rough!
    Peter and I descended into a gutter and then headed towards the reef edge, where a lovely wall drops from 15m to 25m and is decorated with gorgonians, black coral trees, sea whips, tubastra corals and home to abundant fish life.
    Dropping over the wall Peter spotted a small green turtle on the bottom that appeared to be feeding. We headed over, Peter took a few photos and then moved on to photograph a spotted wobbegong, while I moved in to take a few shots.
    This turtle was completely unconcerned by our presence, and continued to feed, ripping out hunks of algae and eating them. I watched it rip chunk after chunk, if the algae clump was too big the turtle would wipe its flipper across its face to reduce the size of the algae. It was quite amusing to watch this, with the turtle taking several swipes each time to break down the algae, but sometimes it would only succeed in knocking it out of its beak.
    After five minutes the turtle drifted off and we continued along the wall, photographing several spotted wobbegongs, a huge pufferfish and a dwarf lionfish. We then came across another green turtle feeding and spotted another one slowly swimming across the bottom.
    Out wide from the wall we then saw something big on the bottom, at first I thought it was a stingray, which are common here, but as we got closer I realised it was a huge green turtle. I have seen thousands of green turtles over the last thirty years, but never one this huge, it was as big as me, its shell close to 2m long. This turtle was also feeding, and as I got closer I could see an enormous tail, half a metre long, a sure sign that this was a male. This guy must have been a hundred years old to be this big. I got a few photos of this monster turtle before it lifted off the bottom and slowly swam away. Peter and I then headed into the main shark gutter and saw more wobbegongs, numerous reef fish, schools of surgeonfish and bannerfish and a few nudibranch before heading back to the boat.
    After a filling lunch, part of the service on Nautilus, the crew decided with such wonderful conditions to head up to Cherub’s Cave, off Moreton Island, for our second dive. It is an hour run up to Cherub’s Cave, so we relaxed as we headed north.
    We were soon anchored at the dive site, which is another grey nurse habitat over winter. The first thing I saw as I descended was a very cute hawksbill turtle swimming amongst a school of bullseyes. While green and loggerhead turtles are the most common turtle species encountered off Brisbane, smaller hawksbills are often seen, and over winter even the giant leatherback turtle makes an appearance.
    I had encountered this hawksbill turtle the last time I dived Cherub’s Cave, almost two years previously, and it was almost like it recognised me as it hung around me for five minutes as I took photos. It slowly drifted over the reef with me, at times peering closely into my wide-angle lens to see its reflection. After five minutes I let this lovely turtle drift off so we could explore the dive site.
    Cherub’s Cave is a fascinating dive site, large boulders in 25m loom up from the bottom and are riddled with caves and ledges. Kelp dominates the bottom, very rare off Brisbane, while the boulders are decorated with black coral trees, soft corals, hard corals and sea whips. As we explored the ledges we found clown triggerfish, anemonefish, moray eels, angelfish, red morwong, snapper and scorpionfish. In one cave was a large brown spotted groper and hidden in the shadows behind it were lots of crayfish. We also saw wobbegongs and bumped into the hawksbill turtle again before our bottom time ran out. Another great day of diving with the turtles of the Moreton Bay Marine Park.

Article appeared in Dive Log No.240 July 2008

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